In just a few days, one of the brightest futures in college basketball has become one of its most uncertain.

Less than a week after Steve Masiello nearly led 13th-seeded Manhattan to a stunning upset over defending national champion Louisville — in the Jaspers’ first NCAA Tournament appearance in 10 years — the 36-year-old coach has been placed on leave by The Bronx school, the latest in a dizzying sequence of events.

As a result, Manhattan has placed Masiello on leave, the school explained in a statement late Wednesday afternoon:

“As a result of a background check commissioned by the University of South Florida, Manhattan College has learned there is a question of the validity of head men’s basketball coach Steve Masiello’s undergraduate degree from the University of Kentucky,” the statement read.

“Masiello is currently in the process of reviewing his degree status with the University of Kentucky. Manhattan College has placed Masiello on leave while he completes this process with the University.”

Masiello attended Kentucky from 1996-2000, where he was a walk-on with the Wildcats, but University of Kentucky officials were unwilling to comment on how many credits Masiello needed in order to earn a degree.

A White Plains, NY, native, Masiello then spent one season as an assistant at Tulane before another four at Manhattan and six more under Rick Pitino at Louisville.

When Masiello applied for the Manhattan head coaching job in 2011, a bachelor’s degree was a listed as a requirement for the position — as it was with South Florida — according to a source familiar with the situation.

Masiello, who has two years remaining on his contract with Manhattan, had agreed to a five-year deal worth more than $1 million per season to step up to South Florida and the AAC.

“During the search for a new men’s basketball coach, an agreement in principle was reached by USF and candidate Steve Masiello,” the University of South Florida said in a statement released Wednesday. “The agreement was pending a verification of credentials. Through the verification process it was determined the candidate’s credentials could not be substantiated and therefore he did not meet the requirements for the position.”

A similar situation occurred at Rutgers last year, when it was discovered that new coach Eddie Jordan did not graduate from the school, though it was not a requirement of the job. Jordan stayed on as coach and is working toward finishing his degree.

After taking over a six-win Manhattan team in 2011, Masiello led the Jaspers to the biggest turnaround in Division I. In his second season, he took an injury-plagued team within one win of the NCAA Tournament, before ending the school’s decade-long drought this month.

On Friday, one day after the loss to Louisville, Manhattan Athletic Director Noah LeFevre told The Post the school would do everything in its power to retain Masiello as coach.

“I’m confident [he’ll stay] because we’re dedicated in doing everything that we can to have him be a member of the Manhattan community for many years to come,” LeFevre said. “I fully anticipate coach being our coach well into the future, meaning beyond his existing contract.”

In just a few days, the future of a near-certain star has become unimaginably uncertain.